共查询到20条相似文献,搜索用时 0 毫秒
1.
《Journal of Modern Optics》2013,60(3):289-300
Expressions have been obtained for the intensity distribution of the fringes in the reflection echelon in the presence of surface errors on the plates. The errors considered are the ones arising during the polishing process, due to inhomogeneous reflection coating, and due to the residual curvature of the plates. These expressions have been utilized for the evaluation of the intensity distribution in a reflection echelon consisting of 20, 30, 40 and 50 plates. Hence permissible errors on the surfaces of the echelon plates have been obtained and it has been confirmed that in order to take full advantage of number N of the plates, surface errors should not exceed 1/4 N of a wavelength in the middle of the visible spectrum. 相似文献
2.
Evaluation of Errors in Calibration Procedures for Measurements of Reflection Coefficient 总被引:1,自引:0,他引:1
《IEEE transactions on instrumentation and measurement》1978,27(4):354-358
Procedures for the calibration of computer-controlled network analyzers in reflection measurements are studied. The major aim of this paper is to develop an error analysis in order to define a quality factor, for evaluating the performances of a calibration procedure. This is done by using the invariance property of the cross ratio, which easily lets one obtain analytical expressions for the residual errors As an application of this technique, a comparison between two actual calibration procedures has been made using an automatic network analyzer. The experimental results favorably compare with the ones obtained on theoretical basis. 相似文献
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《IEEE transactions on instrumentation and measurement》2009,58(4):853-858
5.
Small triple-point-of-water cells (mini-TPW) are used in laboratories to monitor the stability of PRTs. Compared with a standard
TPW cell, heat flow in the thermometer well usually disturbs the apparent equilibrium temperature to a larger extent in a
mini-TPW cell due to its smaller dimensions. In this paper, the heat flow effect is studied on the basis of experimental data.
Special attention is paid to the thermal conduction along a thin thermometer probe and to the self-heating of the probe. A
new method for compensating the error due to the heat flow is presented. It is shown that the compensated results are in good
agreement with results obtained with standard TPW cells. The determined differences were well within the estimated expanded
uncertainty of 2 mK (k = 2). The heat flow effect was studied experimentally by controlling the temperature of the upper part of a PRT inserted
in a mini-TPW cell. Also, the effect of different fillings of the measurement well of the cell was studied. Without the compensation,
thin metal-sheathed PRTs (1.6 and 2.2 mm) indicated 3 to 9 mK differences between mini-TPW and standard TPW cells. 相似文献
6.
This article presents a graphical method to calculate reflection corrections for radiation thermometry. The method is based
on the observation that the measured radiance of a target is a linear combination of radiances dependent on the emissivity
of the target. The method is most easily implemented as a nomogram, enabling thermometer users to estimate reflection corrections
immediately when measurements are taken. The nomogram also provides a visual means of explaining the impact of reflection
errors on measurements and for explaining the impact of measurement uncertainties on temperature measurements corrected for
reflections. 相似文献
7.
Measurement Techniques - Adjustments in the phase structure of optical radiation reflected from a small object with nonlocal coherent reflection and detected by an objective with spherical... 相似文献
8.
Hagen Renner 《Journal of Modern Optics》2013,60(4):673-676
Abstract Polarization dependent corrections to the scalar coupling coefficients of the fundamental modes on two identical optical fibres are calculated from scalar supermode fields corrected up to first order in weak coupling. The method applies to arbitrary refractive-index profiles. 相似文献
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Haiming Wang 《Journal of Modern Optics》2013,60(3):497-505
Abstract In depositing crystalline thin films, anisotropy may be induced by the texture structure of the film. Generally one of the principal axes of this anisotropy is in the direction of columnar growth, which may be neither normal nor parallel to the film surface. In this paper we have developed a general method for characterizing thin films with this kind of anisotropy. Propagation of plane waves in media with the above mentioned crystalline structure has been studied. The reflectance and transmittance of a plane wave from the films with the structure-induced anisotropy have been calculated. By comparing calculations with measurements, we could determine optical properties and thicknesses of the films with the columnar-structure-induced anisotropy. 相似文献
11.
各向异性层合薄板的几何非线性问题,由于控制方程和边值问题求解的复杂性,历来解法繁杂,工作量大且存在较大局限性。本文利用加权残数法简捷,有效的特点,提出以具有良好拟合性和对边界条件灵活可适性的五次B—样条基函数的组合作为试函数基底,然后采用阻尼最小二乘法,应用于解决这类复杂问题。本文在计算时编制了较为通用的程序,若干具体算例表明,本方法收敛稳定,结果准确,且解法简捷,统一,便于程序标准化与推广应用。 相似文献
12.
The formulas for the correct evaluation of dynamic stresses in structurally anisotropic plates are deduced by using the polarization-optical method and the basic relations of photoelasticity. We study the wave field of stresses formed in an anisotropic plate loaded on its free boundary by pulses from a point source and the influence of anisotropy on the character of the analyzed field. The distribution of dynamic stresses induced by a concentrated source is investigated and the dependences of the maximum stresses in quasilongitudinal -waves and Rayleigh waves on the distance from the source are established. 相似文献
13.
应用贝叶斯动态模型理论,探讨了非平稳动态测量误差贝叶斯建模原理及实时修正的方法.由多项式模型、季节模型、回归模型和噪声模型等模型分量组合的贝叶斯动态模型,较好地描述了各种系统误差和随机误差的综合特征,客观反映了动态测量误差的变化规律.利用贝叶斯递推算法和标准信号插入,适时对动态误差模型参数进行调整,以适应非平稳动态误差的时变性,有效控制了动态模型预报精度损失,提高了动态误差实时修正的精度.通过长光栅动态测量系统实时误差修正实例,验证了该方法正确可行,误差修正效果显著,具有较高的应用价值. 相似文献
14.
《Journal of Modern Optics》2013,60(11):857-867
The effect of diffraction grating errors of low spatial frequency is investigated numerically and analytically. 相似文献
15.
《IEEE transactions on instrumentation and measurement》1984,33(2):134-136
A system error of a waveguide impedance bridge due to multiple reflections between the test section and the bridge circuit is analyzed. A principle and a method of making corrections to this system error are presented with actual numerical examples. 相似文献
16.
针对12 Bit量化误差对四参数正弦拟合带来的误差影响,分别在有效位数、幅度、频率、初始相位和直流分量五项参数上进行了拟合误差界的搜索。选取的条件变量分别是幅度、序列所含波形的周波数、初始相位、直流分量以及序列数据点数。以两两联动的双条件组合方式进行误差界搜索,获得了上述五项参数的误差界随不同条件变化而变化的曲线规律,筛分出了显著影响量和不显著影响量,以及明确的误差上界和下界。该结果可用于拟合参数的误差和不确定度估计,也可以在设定拟合误差和不确定度情况下,选择测量条件。 相似文献
17.
It is shown that an expression for the total error as defined in GOST 8.207-76 of the corrected results of a measurement possesses an anomaly when this error is less than one of its components, and that a similar anomaly occurs for the expanded uncertainty as defined in MI 2552-99. The error of uncorrected results of a measurement whose random component is distributed according to different laws is compared with calculations utilizing RD 50-453-84 and MI 1788-87. 相似文献
18.
The relative and absolute measurement errors are examined for devices using constrictions operated under various conditions. The practical metrology of indirect measurements can be based on a principle of equal absolute errors at the boundaries of the measurement range. 相似文献
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